Fabrication and Characterization of YSZ/GDC Bilayer Electrolyte Thin Films by Spray-Coating and Co-Sintering

Abstract

Yttria-stabilized zirconia (YSZ) is the most popular electrolyte material for solid oxide fuel cells (SOFCs). However, when cobaltite-based perovskite cathode materials, for example lanthanum strontium cobalt ferrite (LSCF), are used, an insulating layer is easy to be formed at the cathode-electrolyte interface. For preventing the interfacial reaction, a gadolinium-doped ceria (GDC) interlayer is usually employed between YSZ and cathode. In this work, we investigated the fabrication of YSZ/GDC bilayer electrolyte thin films by a simple spray coating process and co-sintering. Dense YSZ/GDC bilayer electrolyte thin films were successfully fabricated. There is no crack and delamination observed for the YSZ/GDC bilayer. A Ni-YSZ/YSZ/GDC/LSCF-GDC anode-supported single cell with 4 µm thick YSZ layer and 2 µm thick GDC layer shows an open-circuit voltage of 1.1 V and a maximum power density of about 0.6 W/cm2 with humidified H2 as fuel and air as oxidant at 700°C.